oj.uz

Submission #62491

# Submission time Handle Problem Language Result Execution time Memory
62491 2018-07-28T19:11:42 Z zetapi Parachute rings (IOI12_rings) C++14
100 / 100
 2047 ms 85756 KB 
/*
    O(N+M+C) solution for Rings (N = number of vertices; M = number of calls to Link; C = number of calls to CountCritical).
     
    Author: Giovanni Paolini
*/
 
#include <cstdio>
#include <vector>
#include <cassert>
 
 
using namespace std;
 
int const MAXN = 1000000;
 
int n;
bool quadruplication = 0;
 
int numcycles = 0;
int cycle_length; // If numcycles==1, here we store the length of the only cycle
 
int other_endpoint[4][MAXN]; // -1 if the node is not an endpoint, otherwise the other endpoint
vector<int> neighbours[MAXN];
 
int destroyed[4]; // The destroyed node of each graph (only if quadruplication==TRUE)
int degree[4][MAXN];
bool islinear[4]; // Whether each graph is linear or not
 
void Init(int k) {
    n = k;
     
    for (int i=0; i<n; ++i) {
        other_endpoint[0][i] = i;
    }
}
 
void add_new_edge(int x, int y) {
    // Adds an edge in case of quadruplication
     
    for (int i=0; i<4; ++i) {
         
        // Operating on graph i
         
        if ( !islinear[i] ) continue;
        if ( x == destroyed[i] || y == destroyed[i] ) continue;
         
        degree[i][x]++;
        degree[i][y]++;
         
        assert( degree[i][x] <= 3 && degree[i][y] <= 3 );
         
        if ( degree[i][x] == 3 || degree[i][y] == 3 ) {
            islinear[i] = 0;
            continue;
        }
         
        if ( other_endpoint[i][x] == y ) {
            // Cycle!
             
            islinear[i] = 0;
            continue;
        }
         
         
         
        int a = other_endpoint[i][x];
        int b = other_endpoint[i][y];
         
        other_endpoint[i][x] = -1;
        other_endpoint[i][y] = -1;
        other_endpoint[i][a] = b;
        other_endpoint[i][b] = a;
         
    }
     
}
 
 
void quadruplicate (int x) {
     
    quadruplication = 1;
     
    destroyed[0] = x;
    destroyed[1] = neighbours[x][0];
    destroyed[2] = neighbours[x][1];
    destroyed[3] = neighbours[x][2];
     
    for (int i=0; i<4; ++i) {
        for (int j=0; j<n; ++j) {
            other_endpoint[i][j] = j;
            degree[i][j] = 0;
        }
    }
     
    for (int i=0; i<4; ++i) {
        islinear[i] = 1;
    }
     
    for (int k=0; k<n; ++k) {
        for (vector<int>::iterator j = neighbours[k].begin(); j != neighbours[k].end(); ++j) {
             
            if ( k < (*j) )  add_new_edge( k, (*j) );
             
        }
    }
     
}
 
void Link(int xx, int yy) {
     
    int x = xx;
    int y = yy;
     
    if ( quadruplication == 0 ) {
         
        neighbours[x].push_back(y);
        neighbours[y].push_back(x);
         
        degree[0][x]++;
        degree[0][y]++;
         
        // If a node has degree 3, only it or its neighbours can be critical. So we can keep track of each of the 4 graphs obtained by removing one of these 4 nodes.
        if ( degree[0][x] == 3 ) {
            quadruplicate(x);
            return;
        }
        if ( degree[0][y] == 3 ) {
            quadruplicate(y);
            return;
        }
         
        // If their degree is < 3, then they were necessarily endpoints!
         
        if ( other_endpoint[0][x] != y ) { // A longer path is formed
            int a = other_endpoint[0][x];
            int b = other_endpoint[0][y];
             
            other_endpoint[0][x] = -1;
            other_endpoint[0][y] = -1;
            other_endpoint[0][a] = b;
            other_endpoint[0][b] = a;
        }
        else {  // A cycle is formed
            numcycles++;
            if ( numcycles == 1 ) {
                 
                int length = 1;
                int previous_node = x;
                int current_node = neighbours[x][0];
                 
                while ( current_node != x ) {
                    int possibility = neighbours[ current_node ][0];
                    if ( possibility == previous_node ) possibility = neighbours[ current_node ][1];
                     
                    previous_node = current_node;
                    current_node = possibility;
                     
                    length++;
                }
                 
                cycle_length = length;
                 
            }
        }
    }
     
    else {
         
        add_new_edge(x,y);
         
    }
}
 
int CountCritical() {
     
    if ( quadruplication == 0 ) {
         
        switch (numcycles) {
            case 0:
                return n;
             
            case 1:
                return cycle_length;
             
            default:
                return 0;
        }
         
    }
    else {
         
        int answer = 0;
        for (int i=0; i<4; ++i) {
            if ( islinear[i] ) answer++;
        }
        return answer;
         
    }
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 23800 KB Output is correct
2 Correct 24 ms 24188 KB Output is correct
3 Correct 29 ms 24232 KB Output is correct
4 Correct 21 ms 24232 KB Output is correct
5 Correct 23 ms 24232 KB Output is correct
6 Correct 25 ms 24276 KB Output is correct
7 Correct 21 ms 24276 KB Output is correct
8 Correct 32 ms 24276 KB Output is correct
9 Correct 24 ms 24416 KB Output is correct
10 Correct 23 ms 24428 KB Output is correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 448 ms 44652 KB Output is correct
2 Correct 784 ms 63212 KB Output is correct
3 Correct 375 ms 63212 KB Output is correct
4 Correct 1239 ms 63352 KB Output is correct
5 Correct 1247 ms 63416 KB Output is correct
6 Correct 1342 ms 63416 KB Output is correct
7 Correct 359 ms 63416 KB Output is correct
8 Correct 1636 ms 79868 KB Output is correct
9 Correct 2047 ms 85756 KB Output is correct
10 Correct 825 ms 85756 KB Output is correct

Subtask #3
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 23800 KB Output is correct
2 Correct 24 ms 24188 KB Output is correct
3 Correct 29 ms 24232 KB Output is correct
4 Correct 21 ms 24232 KB Output is correct
5 Correct 23 ms 24232 KB Output is correct
6 Correct 25 ms 24276 KB Output is correct
7 Correct 21 ms 24276 KB Output is correct
8 Correct 32 ms 24276 KB Output is correct
9 Correct 24 ms 24416 KB Output is correct
10 Correct 23 ms 24428 KB Output is correct
11 Correct 23 ms 85756 KB Output is correct
12 Correct 27 ms 85756 KB Output is correct
13 Correct 26 ms 85756 KB Output is correct
14 Correct 24 ms 85756 KB Output is correct
15 Correct 32 ms 85756 KB Output is correct
16 Correct 36 ms 85756 KB Output is correct
17 Correct 25 ms 85756 KB Output is correct
18 Correct 27 ms 85756 KB Output is correct
19 Correct 28 ms 85756 KB Output is correct
20 Correct 27 ms 85756 KB Output is correct

Subtask #4
14.0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 23800 KB Output is correct
2 Correct 24 ms 24188 KB Output is correct
3 Correct 29 ms 24232 KB Output is correct
4 Correct 21 ms 24232 KB Output is correct
5 Correct 23 ms 24232 KB Output is correct
6 Correct 25 ms 24276 KB Output is correct
7 Correct 21 ms 24276 KB Output is correct
8 Correct 32 ms 24276 KB Output is correct
9 Correct 24 ms 24416 KB Output is correct
10 Correct 23 ms 24428 KB Output is correct
11 Correct 23 ms 85756 KB Output is correct
12 Correct 27 ms 85756 KB Output is correct
13 Correct 26 ms 85756 KB Output is correct
14 Correct 24 ms 85756 KB Output is correct
15 Correct 32 ms 85756 KB Output is correct
16 Correct 36 ms 85756 KB Output is correct
17 Correct 25 ms 85756 KB Output is correct
18 Correct 27 ms 85756 KB Output is correct
19 Correct 28 ms 85756 KB Output is correct
20 Correct 27 ms 85756 KB Output is correct
21 Correct 42 ms 85756 KB Output is correct
22 Correct 56 ms 85756 KB Output is correct
23 Correct 73 ms 85756 KB Output is correct
24 Correct 52 ms 85756 KB Output is correct
25 Correct 36 ms 85756 KB Output is correct
26 Correct 56 ms 85756 KB Output is correct
27 Correct 76 ms 85756 KB Output is correct
28 Correct 52 ms 85756 KB Output is correct
29 Correct 49 ms 85756 KB Output is correct
30 Correct 125 ms 85756 KB Output is correct

Subtask #5
31.0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 23800 KB Output is correct
2 Correct 24 ms 24188 KB Output is correct
3 Correct 29 ms 24232 KB Output is correct
4 Correct 21 ms 24232 KB Output is correct
5 Correct 23 ms 24232 KB Output is correct
6 Correct 25 ms 24276 KB Output is correct
7 Correct 21 ms 24276 KB Output is correct
8 Correct 32 ms 24276 KB Output is correct
9 Correct 24 ms 24416 KB Output is correct
10 Correct 23 ms 24428 KB Output is correct
11 Correct 448 ms 44652 KB Output is correct
12 Correct 784 ms 63212 KB Output is correct
13 Correct 375 ms 63212 KB Output is correct
14 Correct 1239 ms 63352 KB Output is correct
15 Correct 1247 ms 63416 KB Output is correct
16 Correct 1342 ms 63416 KB Output is correct
17 Correct 359 ms 63416 KB Output is correct
18 Correct 1636 ms 79868 KB Output is correct
19 Correct 2047 ms 85756 KB Output is correct
20 Correct 825 ms 85756 KB Output is correct
21 Correct 23 ms 85756 KB Output is correct
22 Correct 27 ms 85756 KB Output is correct
23 Correct 26 ms 85756 KB Output is correct
24 Correct 24 ms 85756 KB Output is correct
25 Correct 32 ms 85756 KB Output is correct
26 Correct 36 ms 85756 KB Output is correct
27 Correct 25 ms 85756 KB Output is correct
28 Correct 27 ms 85756 KB Output is correct
29 Correct 28 ms 85756 KB Output is correct
30 Correct 27 ms 85756 KB Output is correct
31 Correct 42 ms 85756 KB Output is correct
32 Correct 56 ms 85756 KB Output is correct
33 Correct 73 ms 85756 KB Output is correct
34 Correct 52 ms 85756 KB Output is correct
35 Correct 36 ms 85756 KB Output is correct
36 Correct 56 ms 85756 KB Output is correct
37 Correct 76 ms 85756 KB Output is correct
38 Correct 52 ms 85756 KB Output is correct
39 Correct 49 ms 85756 KB Output is correct
40 Correct 125 ms 85756 KB Output is correct
41 Correct 262 ms 85756 KB Output is correct
42 Correct 789 ms 85756 KB Output is correct
43 Correct 268 ms 85756 KB Output is correct
44 Correct 341 ms 85756 KB Output is correct
45 Correct 484 ms 85756 KB Output is correct
46 Correct 785 ms 85756 KB Output is correct
47 Correct 1196 ms 85756 KB Output is correct
48 Correct 311 ms 85756 KB Output is correct
49 Correct 790 ms 85756 KB Output is correct
50 Correct 865 ms 85756 KB Output is correct
51 Correct 256 ms 85756 KB Output is correct
52 Correct 315 ms 85756 KB Output is correct
53 Correct 326 ms 85756 KB Output is correct
54 Correct 1266 ms 85756 KB Output is correct
55 Correct 526 ms 85756 KB Output is correct